Mercury-vapor apparatus.



PATENTED MAY 26, 1908.

. P. H. THOMAS.

MERCURY VAPOR APPARATUS.

APPLIOATION FILED JAN. 6 1904.

INVENTOH M mg.

.ATTOHN WITNESSES rr snares PATENT OFFICE.

PERCY H. THOMAS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO COOPER HEWITT ELEC- TRIC- COMPANY, OF NEW YORK, N. Y., A CORPORATION OI NEW YORK.

MERCURY-VAPOR APPARA'ITIS.

To all whom it may concern:

Be it known that I, PERCY H. THoMAs, a citizen of the United States, and resident of 'East Orange, county of Essex, State of New Jersey, have invented" certain new and useful Improvements in Mercury-Vapor Appa-'" tuted for theusual container of such apparatus, and it was found that ozone was generated to such an extent that its effects were too serious to be borne by theo 'erators of the apparatus for any considerab e length of tlme. i

The present invention is designed to overcome the difliculties connected with the generation of ozone or other troublesome gases by the passage of current between electrodes inside a silica container, by surrounding the whole apparatus with a screen made of material which is more or less impervious to the ultra-violet rays. Such a screen might be made of ordinary glass, and the simplest embodimentof the lnvention would consist of a mercury vapor lamp having a container made of silica, the said container-being surrounded by a screen of glass. The invention, is,however, equally applicable to any apparatus in which electric current is passed between electrodes or circuit terminals inside a container of silica.

I have chosen to illustrate the invention in connection with a mercury vapor lamp, the drawing showing avertical section of such a lamp having a container of silica, surrounded by a screen of glass.

In the drawing, 1 is a container of silica, and 2 and 5, respectively, positive and negative electrodes within the container. The electrode 2 may be of iron or any other suitable material and the electrode 5 may be of mercury or other volatilizable material suited for the pur osc. Lead-wires, 7 and 8, lead, respective y, to the positive and negative electrodes through the walls of the silica container.

In general, the apparatus thus far de- Specification of Letters Patent.

,Application filed January 6, 1904. Serial No. 187,891.

Patented May 26, 1908.

scribed is similar to the well-known mercury made of silica instead of glass.

In order to obviate the difliculties connected with the operation of a lamp such as would be constituted by the devices already described, I surround the said lamp with a screen, 6, of glass, which is impervious to the ultra-violet rays.

I claim as my invention:

1. The combination with a closed holder of silica, electrodes therein, and lead-wires for connection with an external circuit extending to the electrodes, of a screen surrounding the said holder, the said screen being of a material which is substantially impervious to ultra-violet rays.

2.-A mercury vapor electric lamp comprising a closed container of silica, a positive and a negative electrode therein, leadwires for connecting the said electrodes with an external circuit, the said container being sur-- j rounded except at the portions traversed by the lead-wires by a screen of material impervious to ultra-violet rays.

3. The combination with a closed holder composed of a material which is pervious to ultra-violet rays, electrodes therein, and lead-' wires connecting the said electrodes to an external circuit, of a screen surrounding the said holder, the said screen being of a material which is substantially impervious to ultra-violet rays. f

4. In a Vapor electric apparatus, the combination of a closed tube pervious to actinic rays, electrodes therein, lead-wires connecting the said electrodes with an external circuit, a screen impervious to actinic rays surrounding the tube, and a conducting vapor within the tube through which current is adapted to pass.

5. In a vapor electric apparatus, the combination of a closed quartz tube, electrodes therein, lead-wires for connecting the said electrodes to an external circuit, a glass tube surrounding the quartz tube, and a conducting vapor within the uartz tube through which the current int 1e vapor medium is caused to pass.

6. In a vapor electric apparatus, the combination of a closed tube pervious toultraviolet rays, electrodes therein, lead-wires for connecting the electrodes with an external circuit, a screen impervious to ultra-violet rays surrounding the tube, and a conducting loo vapor within the tube through which electric proportioned as to leave a space between the 10 current is adapted to pass. said holder and the said screen.

7. The combination With a closed holder Signed at New York, in the county of New of silica, electrodes therein, and lead-Wires York, and State of New York, this 16th day for connection With an external circuit exof" December, A. D. 1903 tending to the electrodes, of a screen sur- PERCY H. THOMAS. rounding the said holder, the said screen Witnesses: being of a material which is substantially WM. H. CAPEL,

impervious to ultra-violet rays and being so GEORGE Hj STOCKBRIDGE. 

